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15 hours ago, Iank said:

Thanks so much for this thread, started repairing a vl commodore & eventual restoration.

Invaluable help for replacing this fittin that I am about to do. Just wondering where the lowest cost fitting can be bought from, the one in the pic looks like stainless.

Also I'm going to have to replace the front fitting on the thermostat housing, which looks like a bit of a nightmare as its pressed in, so wondering if someone has done it & how. Any help appreciated.

Yeah the front fitting was bad enough I didn't even try. Mercifully it wasn't pitted after sanding off the corrosion. I believe it's pressed in so I have no idea how you would get it in or out without pulling the engine.

Probably the cheapest way is to use plumbing solder to fill the pits in after cleaning out the rust.

  • 1 month later...
On 11/2/2021 at 1:45 AM, GTSBoy said:

Win.

Sealant is not an (all purpose) replacement for thread tape. In such an application (and for gas fittings, which I assemble a lot more of than I should) I always use tape and sealant. Coolant and even fuel fittings on cars can deserve both. The thread tape is more of a mechanical thing that jams up in the threads and as you have found, can arrange for the thread to lock up at the right orientation.

The goop does what it says on the box. makes damn sure it won't seal.

Thread sealant is generally the better choice and not to be mixed with tape. Some of the rare cases sealant is not recommended is on non PTFE plastics, freons and anything to be used with food or beverage. Thread sealant is also always the better choice for gas. Unfortunately its biggest down fall is having to wait for it to cure before putting it back into service.

Another issue with Teflon tape and most gases is the wrong Teflon tape is often used... White Teflon tape belongs in your kitchen and bathroom and that's it unless using very expensive products like Swagelok whose white tape is universal. 

 

  • Like 1
11 minutes ago, TurboTapin said:

Thread sealant is generally the better choice and not to be mixed with tape. Some of the rare cases sealant is not recommended is on non PTFE plastics, freons and anything to be used with food or beverage. Thread sealant is also always the better choice for gas. Unfortunately its biggest down fall is having to wait for it to cure before putting it back into service.

Another issue with Teflon tape and most gases is the wrong Teflon tape is often used... White Teflon tape belongs in your kitchen and bathroom and that's it unless using very expensive products like Swagelok whose white tape is universal. 

 

SWM000534B01V0001.jpg?20220926123636

Industry standard. Almost compulsory on all natural and LP gas thread4d connections. Trusted by every gas fitter the world over.

No-one uses white tape. This is yellow, is at least double the thickness of typical good white tape. Is at least 4 tmes the thickness of cheap Bunnings tape.

47 minutes ago, GTSBoy said:

SWM000534B01V0001.jpg?20220926123636

Industry standard. Almost compulsory on all natural and LP gas thread4d connections. Trusted by every gas fitter the world over.

No-one uses white tape. This is yellow, is at least double the thickness of typical good white tape. Is at least 4 tmes the thickness of cheap Bunnings tape.

That 4$ role of Teflon tape might be standard practice and do a great job in low pressure residential, commercial and industriel fuel gas connections with mercaptan present and the dangers of a leak are minimal but it is not standard in the rest of the oil and gas industry.

I work for one of the largest oil and gas pipeline companies in North America. The only teflon tape allowed on any site is swagelok tape and it's not cheap. 

 

You don't use thread connections on anything larger than 40-50mm and certainly not on high pressure applications, so the point is moot.

the fact remains that for pressures up to about 100kPa and small pipe sizes on distribution and appliance pipework, ANY threaded connection will be gas taped and probably with sealant as well. Almost never with sealant only.

19 minutes ago, GTSBoy said:

You don't use thread connections on anything larger than 40-50mm and certainly not on high pressure applications, so the point is moot.

the fact remains that for pressures up to about 100kPa and small pipe sizes on distribution and appliance pipework, ANY threaded connection will be gas taped and probably with sealant as well. Almost never with sealant only.

Incorrect. Our pipelines generally see 7000+ kpa and so do all those small instrumentation lines with threaded fittings. Swagelok Swak thread sealant for example is rated to 69000kpa. 

As for mixing tape and sealant, find me one oem document that recommends it? I've also heard of low pressure pipe fitters doing this but it doesn't make it right. 

4 minutes ago, TurboTapin said:

As for mixing tape and sealant, find me one oem document that recommends it? I've also heard of low pressure pipe fitters doing this but it doesn't make it right.

You don't need an OEM document. You need the Australian Standard AS 5601, and the technical bulletins issued by Energy Safe Victoria, Building and Energy Western Australia, their equivalents in all the other states (who generally just look to ESV for guidance because ESV usually get to the correct technical outcomes before anyone else, and who are supremely technically competent as gas safety regulators).

Something to remember about gas safety. In the US there is NFPA 86, created by the NFPA of course, and policed......by......nobody. At least the Canadian standards are a bit better enforced. My company did the flames for the Vancouver winter olympics, including all the controls and pipework and burners. I know what it's like to get stuff approved in Canada. But Australia? It is like no other place in the world. AS 3814 is widely recognised, amongst people who are aware of many international gas appliance standards (ie NFPA 86, ISO 13577, EN 298, EN 746.2, the various otthers like Japan's, the GOST crap in far eastern Europe, and so on), as being the hardest to comply with because of its complexity. We have to design equipment to comply with 3814 and we have to completely and utterly prove that it meets every applicable part of the standard to a gas inspector in the state where the appliance is being commissioned. And the gas inspectors? They like to see tape and sealant on threaded pipework.

I have a question. If you are using Swagelok, why are you using tape at all? For your high pressure small pipework, why not just swage onto the tube and rely on the Swagelok fittings? I mean, it's not as if you're allowed to use tape in a conical seat fitting anyway. I would have thought that you would be using pressure indicators and transmitter and nipples on the pipework that were fully welded Swagelok.

Here in Australia, we seldom kill anyone with gas appliance explosions, despite the fact that they are looked after by just low pressure gas fitters. I can't think of one incident. The most lethal incident in Australia? In the oil and gas industry. Look up Longford. We (the rest of industry) tend to treat the oil and gas guys as a law unto themselves because they reckon they know everything, even though they have a track record of massive f**kups. It used to be that if you worked for Chevron in Western Oz, you were the big swinging dick in your social circle. Now, oil and gas is such a dirty word that no-one confesses that they still work for them. Most of that is environmental, but a large part is also the expensive failures in the industry over the last 20 years.

  • Like 1
4 hours ago, TurboTapin said:

Thread sealant is generally the better choice and not to be mixed with tape. Some of the rare cases sealant is not recommended is on non PTFE plastics, freons and anything to be used with food or beverage. Thread sealant is also always the better choice for gas. Unfortunately its biggest down fall is having to wait for it to cure before putting it back into service.

Another issue with Teflon tape and most gases is the wrong Teflon tape is often used... White Teflon tape belongs in your kitchen and bathroom and that's it unless using very expensive products like Swagelok whose white tape is universal. 

 

I could've waited months for everything to set, I just figured thread sealant didn't make sense because it wouldn't provide resistance/structure like teflon tape. Presumably I could've used thread sealant by just tightening to the same number of turns but it genuinely felt loose so I was worried it would work itself loose even if the thread sealant had set. Another person I saw working on this engine used RTV instead so clearly I was not the only person concerned about this fitting working itself loose, I just hate the idea of using something that would almost certainly make it incredibly annoying to remove in the future.

6 hours ago, GTSBoy said:

You don't need an OEM document. You need the Australian Standard AS 5601, and the technical bulletins issued by Energy Safe Victoria, Building and Energy Western Australia, their equivalents in all the other states (who generally just look to ESV for guidance because ESV usually get to the correct technical outcomes before anyone else, and who are supremely technically competent as gas safety regulators).

Something to remember about gas safety. In the US there is NFPA 86, created by the NFPA of course, and policed......by......nobody. At least the Canadian standards are a bit better enforced. My company did the flames for the Vancouver winter olympics, including all the controls and pipework and burners. I know what it's like to get stuff approved in Canada. But Australia? It is like no other place in the world. AS 3814 is widely recognised, amongst people who are aware of many international gas appliance standards (ie NFPA 86, ISO 13577, EN 298, EN 746.2, the various otthers like Japan's, the GOST crap in far eastern Europe, and so on), as being the hardest to comply with because of its complexity. We have to design equipment to comply with 3814 and we have to completely and utterly prove that it meets every applicable part of the standard to a gas inspector in the state where the appliance is being commissioned. And the gas inspectors? They like to see tape and sealant on threaded pipework.

I have a question. If you are using Swagelok, why are you using tape at all? For your high pressure small pipework, why not just swage onto the tube and rely on the Swagelok fittings? I mean, it's not as if you're allowed to use tape in a conical seat fitting anyway. I would have thought that you would be using pressure indicators and transmitter and nipples on the pipework that were fully welded Swagelok.

Here in Australia, we seldom kill anyone with gas appliance explosions, despite the fact that they are looked after by just low pressure gas fitters. I can't think of one incident. The most lethal incident in Australia? In the oil and gas industry. Look up Longford. We (the rest of industry) tend to treat the oil and gas guys as a law unto themselves because they reckon they know everything, even though they have a track record of massive f**kups. It used to be that if you worked for Chevron in Western Oz, you were the big swinging dick in your social circle. Now, oil and gas is such a dirty word that no-one confesses that they still work for them. Most of that is environmental, but a large part is also the expensive failures in the industry over the last 20 years.

We are not bound to any of those appliance or fuel gas standards. We're a federal company legally bound to pipeline standards (ex: CSA Z662) which we actively take part in writting. We are at a much higher pressure, see H2S and our gas doesn't stink like mercaptan thus the risk of a leak is much higher. They are enforced by the CER in canada and the FERC in the US who do yearly site visits and all new constructions have full time inspectors. Leak detection and repair is a very heated topic. If in any of those standards it states using both tape and dope/sealant is fine or makes reference to a procedure to do so, I'd love to see it. 

Our tubing generally starts and stops with a threaded fitting. Our above ground pipelines are riddled with tubing and threaded fittings for instrumentation. Underground portions have everything welded.

Tape will often be just fine, but at the end of the day if you can wait out the 24h cure, thread sealant alone is the better option. 

 

3 hours ago, joshuaho96 said:

I could've waited months for everything to set, I just figured thread sealant didn't make sense because it wouldn't provide resistance/structure like teflon tape. Presumably I could've used thread sealant by just tightening to the same number of turns but it genuinely felt loose so I was worried it would work itself loose even if the thread sealant had set. Another person I saw working on this engine used RTV instead so clearly I was not the only person concerned about this fitting working itself loose, I just hate the idea of using something that would almost certainly make it incredibly annoying to remove in the future.

Teflon Tape will be just fine in your application. First time I hear of anyone using RTV on threads. 

 

8 hours ago, TurboTapin said:

Teflon Tape will be just fine in your application. First time I hear of anyone using RTV on threads. 

 

You clearly have never seen Japanese mechanics in action then, they use RTV anywhere and everywhere. I hate using RTV because it requires more than zero skill to prep and apply it. 

  • Haha 1

I should post up the photos of a 12" flange where the knuckle dragging mechanical fitter put RTV in a zig-zag line running inboard, then outboard, of every other bolt around the flange. 100 kPa gas pressure inside had no difficulty finding its way to the 5% of bolt holes with no RTV between them and the gas pipe.

And that's before you realise that you don't even need or want RTV on such a flange unless it is quite severely deformed in fabrication.

  • Haha 1

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